Check out the fun Easter Egg behind Facebook’s notification sound

Ping! Remember when Facebook rolled out a featured that included an audio notification you every time your friend sends you a message or comments on a post? As annoying (or soothing) as that sound might be to you, here’s one detail that Buzzfeed reported about the sound that you haven’t noticed.

Listen to the notification very carefully. Can you make out the chord? If you’ve never taken a music class, then you’re probably stumped. And even if you did, perhaps your pitch isn’t quite perfect. So let’s just go ahead with the big reveal.

If we break the chord down into the individual notes, the first is an “F.”

Then an “A”.

Followed by a “C”. Are you seeing where this is going?

Yep, and finally there’s the “E” that you were expecting.

See the trend here? That notification is actually, literally, putting the “FACE” in Facebook.